Detaching means for abrasive disks



Nov. 3, 1953 A. TURToN ET AL DETACHING MEANSl FOR ABRA'sxvE DIsKs 2 Sheets-Sheet l Filed April 2, 1951 Nov. 3, 1953 A. TURTON ET AL DETACHING MEANS FOR ABRAsIvE Drsxs 2-Sheets-Sheet 2 mfw m.. N r l .0l/4 A www MM 2k my* Filed April 2, 1951 Patented Nov. 3,

-U-N-ITEB :is TATES PATENT referme ArthurTurlton and IIenrygEl'bert-Hickmam "136s ngeles, Calif.

vfi.Appli@Letti0h,"*April-@2, 1951, Serial No. 218,819

'fthe :title @indicates @the :present iinventi'en .concerns :abrasive .cdisc'si and @fi-n particular with means' tofatta'c'h and 'detachlsueh .1 discslupon the driven f'arborf of; a manually manipulated .motor :for .use .in fgrinding, ..blifng f'andapelishing--fsheet metal, partieularlyethe:sheetmetal Wnrkeof; automobiles and athe like.

Automobilessheetimetalzrepair :iandl paintzshaps Y nd Litlinecessary fitoraise a-fsuecession off abrasive discssupon yasinglejoh- Whichidiseseareespeeializedfforiparticularr operations, that;is,.=;some discs :are formedewithizcburse :abrasive material .forrnfast cutting 4orfrolughingein, whilenothers :are v4fori-ned .withudifferentf'degreesaof -nenesszot abrasive .materiallor finishing Work. @Onsthejobithere sa natural sequence in the selection of the .discito Ibe iused which is primarily determined by,..the sconditioneof thezworksandtlfre degreeaoisinnoth- -Lnessztofbezgiven thereto,r andnsucheselectionzigenferallyy r-.unssfrom ethe AcourseA .to the fmediumzfarrd rthento ,the-line Abrasive ;discs Vfor tthisst-ype ef fvvorrk arefeenzt'ere'd uponlfa head i'attached; to ethefimotorshafft fa'ndaref held compressedebetweenesuchfheadLand fa flexible .disogistiffener @thereon fand 2 a relatively Ylarge,flatlfreetdelsriutithreadedly fattachedzth-ere- Lto, thus `rtol change frompne disc tto anotherere- 'qluires the luse @of ia awnench @to fhold the head .against:torque. appliedatofitheinutrbyzthezusecoffa 'second wrench.

-ltlwill Vthus berseen:that;thetelrangedisesiini'the presently customaryrmannervisbsloweand.*cumber- .zsome :in Ssueh degrees-as 1 to @cause -1 many workmen toJattempttorlnishta "surface with a Ldiselw-lfiiczh is not :adapted byitsgneness 5to .the :nish :re- :qured merely in,` zan @attempt to iobtainfgreater output fof `volume-t of Workso that ina-manywcases @the :surface ,being workedais aneedlessly;V scored =s0 that.re'-Working thereof lis requirediorethe 4useroi .'lling materials :prior :gto painting 4:must ebe Eresorted 4to,'neither of .which operationsf are orA can be justied in theerstinstance,ebutrwhiehado represent ,a condition eurrentlygpresent infmany fshops, and inz otherinstancesa vWorkman because of-,loss of Atime in*v conventionallyfvchanging -from :.avne to va-courser=disc'Willundertalm to @use-a rline disc upon a paintedesurfacewhereby-under Afrietionally Ygenerated "heat the paint `will f completely -floul the `sanding' disci toithe. complete ruin ythereof whereby needless expense and .further lossrof time are incurred.

Accordinglyand.A in View of -this. condition.it.is va primeobjeetof the invention `to provide. anovel, .yet simple method for pyramided positioning f .sanding `discs upon alrotatable...supportheadand volants. (clear-T197) 2 fer-thefaelefelialigeiever 'item1 ones-to `ranother Afor ffu-rictienalfn Jtlfiereef.

iAnotheriebj'eci-,i ofitheiinvent-iemresides inithe novel construction-Sand 4cernleerla-tie'n Iof iii-iat- 'headedidiscesu'ppofftttingssoL-arrangedwth'respect to one another as to beaperableitorelease sa-icldise 1Witheut1teels andfwhereby saiddisamay be held compressed therebetween and agains'tza backing discllfonunctionallusesthe said-'sanding disc fbeingireleasablefrom betweenfthettings upon rand byfeounterrotation thereof @with ire- -spect Lto :another discrheldebetweenoneafofthe?tv tings-rantifa retatafble support-:flieadfenzthe driving motor.

-iifurther :object of tithe lrinvention. resides in :novelrprovisionof -tongue and slotarneans:E to re- .-.lea'sab1y eoupletelamping .z elements 'srvherehy .A one element thereof-having@asanding disc centered thereon isheld:underfspringtpressure to releasably clamp said disc for use.

ethemebiects, lifeatures and advantages :of the invention may be noted from. aestud'y ofethadraw- Lingnthei.detaiiedtdescriptienzthereof 'andthe-sub- .eioined zelaims.

:In lthe drawing:

V:liigure 1 fis sa top-.plan (viewlzshowin-g cabra-sive roizlfsanding-zfdises: mounted fon functionalusetwith- @the:purviewfioftths einvention.

Figure 2 is a side-elevational View shotvingxthe -abrasi-ve :,-dises illustrated :in Figure Lf1 and also showing in dotted-linesfthetmannerl in which Ythe fdiscs fare'fmanipulated for :,:quick `change of the :upper l'mostzonerthereoii thatyisetherlower disc is =bent fsl-ightlydownward: forhandigrasp holding fwhi1e the upper disons slightly ,sprung or bent "up Wardlyegandsis ethen manually rota-ted 1in a @dix rection counter ato 'Y the f running of the threads f as .indicated by f the arrow.

Figure f3 ,is a `transversesectional View through a disc-:and the fserewttingfrelated' in vuse ,ftheretd .theyiew also :showsa small-fannularygroove-under -;the [head :of the ditting which theydisc -is ls upponteclffprer to fassemhlyaseshown in vligure 2;.211141 ,Y e ,K eliigure :eis-.a simi-lar ftypefi-llustration-.exeeptng that here the disc is assoeiated witha fitting -adapted tgthreadedly receive ithej nut .or lit-,ting shown in Figure v4Stand:isAitselfadapted ,to be fthreadedlv received :in the v-retatalele head .shown -in Figure 2 l'for..mountingl1pon theshaftf :a motor. l

ff acentos 3 in section the whole of the assembly comprising this invention; while,

Figure 7 is a transverse sectional View taken substantially along line 'i-l, Figure 6, to show the relative position of the ttings used to support the disc when assembled.

In Figures 8 through 16 we show another form of mounting sanding disc upon an arbor wherein the essential feature resides in the ease and general facility with which these discs may be changed for specialized use; and wherein,

Figure 8 is a top-plan view of the assembled discs generally related and similar in appearance to the illustration shown in Figure l.

Figure 9 is a side-elevation showing the assembled discs in their relation to the motor driving means.

Figure l is a view showing the disc support head in transverse section and showing the disc clamping means in side-elevation excepting that a portion of the first or primary fitting is broken away to facilitate illustration of the slot"I through which the secondary iitting is withdrawn for release of the upper-most disc.

Figure ll is a side-elevational view of the sec# ondary fitting; and,

Figure l2 is a similar view of the primary fitting.

Figure 13 is in general a transverse sectional view showing all of the parts of the assembly.

Figure le is a transverse sectional View taken along line Iii-lt, in Figure 10 showing the slot and bayonet relationship between the primary and secondary fittings.

Figure 15 is a top-plan view of the secondary fitting as seen along line l-l5, Figure 12, the view is generally intended to show the slot therein through which the pin or bayonet in the primary tting is withdrawn for release of the primary fitting; and,

Figure 16 is a mid-vertical transverse sectional view thereof.

Figure 17 is a view in mid-vertical section showing the primary tting and the rotatable head in socketed union and wherein these two structural elements of the invention are both screw threaded upon the driving shaft of the motor whereby they are held in unitary relationship.

In the drawing the reference character l indicates a plurality of abrasive discs 2 and 3 of which for the purpose of this description, disc 2 will be considered as being nner than the disc E, that is, the grit or abrasive material forming the work surface thereof is ner or smaller than that of the other disc. The construction of these discs and the nature of the abrasive material thereon is quite immaterial to this invention for the reason that they are conventional items available to the trade, and all such discs are formed with a central opening for positioning upon an arbor or other centering support which in the present instance comprises a rotatable head 4 which is mounted upon the shaft 5 of a motor t, a fragment only of which is shown in Figure 2.

The disc supporting head i is annular in transverse section for static balance and is formed with a cylindrical portion 6 having an annular iiange 'i formed with a concaved top surface la upon which the discs 2 and 3 and a semi-resilient non-abrasive support disc or backing are positioned as shown in Figures 2 and 6. The support disc 8 may be formed of Micarta, stiff rubber or other equivalent material which is semiflexible for the reason that its primary duty is to provide a backing for the discs 2 and 3 whereby these working discs may be forced into yielding contact with the surface of the sheet metal being worked.

The medial vertical center of the head i is bored at 4a therethrough and this bore is threaded at 9 in the lower end thereof to receive the shaft 5 of the motor 6, and is tapped with fast running threads il) in the upper end por- Y tion to receive like formed threads lila upon the lower exterior body of the primary fitting il.

The primary tting H is formed with a body l2 having the aforementioned fast running threads lila and with a concaved flange is the lower surface I4 of which is disposed at an angle substantially parallel with the degree of angularity of the concaved upper surface of the head i whereby upon assembly of the unit as shown in Figure 6, the flange surface It and the flange surface la constitute pressure surfaces to firmly secure the sanding discs 3 and the resilient backing disc 8 in functional use position. The upper surface l5 of the ilange i3 lies substantially parallel with the lower surface i4 thereof. A small annular groove It is cut in the outer wall of the part l2 adjacent to and under the flange i3 to form a seat or point to engage the wall of the opening common to all discs of the character herein contemplated for use. In practice the body l2 of the fitting ii is inserted and centered in the opening in the disc as shown in Figure 4 so that thereafter the dise can be forced into the groove i6 as shown for temporary retention of the disc upon the fitting.

The primary fitting Il is bored medially and longitudinally of its length and is tapped with course or fast running threads il to receive like formed threads l'i'a upon the body I8 of the secondary fitting I9 as illustrated in Figure 3, wherein it will be noted that this iitting is also provided with an annular flange 29 the under surface of which is angularly aligned with the iiange l5 on the primary fitting ll. A small annular groove 2l is formed in the exterior surface of the body it adjacent to and at the point of beginning of the flange 2B to form a seat or place to retain the sanding disc 2 therein upon assembly of this disc and fitting for temporary unitary relationship thereof when disassembled from the remainder of the unit.

From the preceeding description it is believed that it will be apparent that the head d will threadedly receive the primary fitting il with the disc 3 seated in the groove I6, and that the primary fitting will threadedly receive the secondary fitting I9 with the disc 2 seated in the annular groove 2| therein and that these nttings and discs including the backing disc 8 will stand in nested position and relationship substantially as shown in Figure 6.

Ordinarily the upper disc 2 is `course for fast cutting. After completion of roughing in the work it becomes necessary to smooth the worked surface and free it of scoring caused by the courser abrasive, to bring the disc 3 into play for fine sanding it is only necessary that each of the discs, that is discs 2 and 3 be grasped along their periphery and with one hand holding the lower disc stationary, the other hand rotates the upper disc in a lcounter-direction to the running of the threads whereby the secondary fitting is threadedly disconnected from the primary fitting whereupon the fine sanding disc or disc 3 in the presetbide'r isuifcoieiedfriis 4{t'i's 'tobe noted thattliforedsoribedoperation iS at complete variance with current practice wherein itis necessary to employ wrenches to disconnect asingle `disc f'rom vthe 'head IlY and-'thereafter Y9btain and by using wrenches again threade'dly insert the desireds'andingfrdisc is thisin'cenvenience `rof operation which 4causes many workmento sluff* and infmany cases-:cause :of the part Vworked*Y upon or to sonearly ruin `the work that extensive reworking thereof `Ais required.

In Figures 8-16 we show another form of structure adapted to effect easyand quick interchangeability of the sanding discs 2 and 3, which as shown in Figures 10 and 13 are also supported by a resilient backing disc 8, and wherein this latter disc and the sanding discs 2 and 3 are all held in releasable clamped position upon a rotating head 22 which is in general constructed in the form of its counter-part 4 as shown in Figures 1-8, that is, it is formed with a bore 23 having a lower threaded end for threaded union with the motor shaft 5 and with course or fast running threads 24 to receive the like threaded shank of the primary fitting 25, which fitting is also formed with a medially and longitudinally disposed bore 26 which differs from the bore 4a in fitting Il in that it is not threaded, but is adapted to slidably receive the cylindrical body 21 of the secondary fitting 28.

Slots 29 are cut through the wall of the primary fitting to receive and guide the free ends of a pin 30 which extend through elongated slots 21a formed in the body 21 of the part 28, and these slots have an upper curved side 3| whereby one end of the slot forms a pocket 29a wherein the pins are retained under spring pressure as -will be subsequently po-inted out, while the other end of these slots extend more or less vertically through the wall of the ,fitting to terminate in the annular recess 32 in the top thereof whereby the fitting 28 and the pins 30 associated therewith may be inserted into and withdrawn from the bore 26 for functional use assembly.

An annular flange 33 is formed upon the tting 25 to provide a pressure surface for securely holding the backing disc 8 and the sanding disc 3 upon the head 22, while a small annular groove 34 in the under-surface of the flange is adapted to receive and detachably support the disc 3 therein against dislocation by minor force.

The secondary fitting 28 is provided with an annular flange 35 extending from the body thereof and this fiange is also provided with an annular groove 28a upon its lower side to receive and support the sanding disc 2 against dislocation by minor force. The cylindrical body 21 of the fitting 28 is formed with a medial longitudinally extending bore 36 to receive a finger actuated depressable plunger 31 through which there extends the pin 30 aforementioned, and the cylindrical walls thereof are formed with the elongated slots 21a through which the pin 30 project for movement through the slot 29 in the primary iitting 25. The lower end of the bore 36 is closed as by the end wall 39, and a spring 38 is sealed under tension within the bore 3B with its one end pressing against the closure wall 39 and its other end pressing against the lower end of the plunger 31 whereby the plunger is normally held in an upper most position, which position is limited by the upper end of the slot 21a when dis-assembled from the unit as a whole, or

itejrativiy {ity fthe slet 129 :when fassenitiei pstin within the *primary 'fitting iI7 shows I'a modiiication of rstructiiie which 'isi primarilyfv doncernediwith lowering vSproductionfcdsts, 'here-the rotatable *head'f4-is formed with'iabdrellb having fsmoo'th sidewalls 94e and tlielprirnaiyfitting "lf2'jin-lieu of "the threads ma is formed with smooth 1"exterior rwalls .ff2'a ffor s'cl'tin intthebo'reillh The lowerlen'do he head "f4" closely s'envel'opsjthe motor fshaft 3vt fand the j'fitting *l2 is centrally bored *and internally threaded fat `*|j'2b tfor *screw "threading 'upon "the tts wh rebyiwhenassembied'as shown the""'drawiiig these two structural 'elements 'are securely Yj oiried for :"holding :the disc t8 nand "the disc 3 in functional use position and, the fitting I2 when thus 'positii'nedupdnftlie motor shaft 5 is'aidiapte'dito thie'ade'dly "receive the secondary fitting I9 threadedly positioned therein so that with respect thereto, the nal assembly of the several mechanical parts including the abrasive discs 2 and 3 and the backing disc 8 have in general the appearance of the assembly shown in Figures 1 and 2.

Assembly and dis-assembly of the primary and secondary fittings 25 and 28 with the discs 2, 3 and 8 is believed to be obvious from the preceding description, however, it may be stated that ordinarily the disc 3 remains inthe assembly upon the fitting 25 until worn out whereupon this fitting is unscrewed from the head 22 by grasping the rim of the disc and rotating it counter to the running of the threads 24 whereupon a new disc is or may be installed in the manner aforestated.

As previously stated the use of a power sander requires the alternate use of a line sanding disc and a courser one as at 2 and 3. After using the courser disc 2 and if it is desired to use the fine disc 3 it is only necessary to depress and rotate the plunger 31 so that the pin is released from the pocket 29a for freeing the part 2'1 from within the slot 29 whereafter the secondary fitting 28 may be withdrawn from the primary fitting 25. To again use the disc 2 the secondary fitting is installed to use by a reversal of the afore-described dis-assembly thereof.

Having thus described our invention in its presently preferred form but without being specifically limited thereto, that which we believe to be patentably novel and for which we seek Letters Patent is as follows:

We claim:

1. The combination in a portable electric motor having a sanding disc support head secured to the shaft of the motor for rotation therewith, of means to detachably secure a plurality of sanding discs on said support head, said means comprising an arbor for each of the sanding discs on the support head, said arbors being formed with threads thereon and therein for threaded connection with one another and with a screw threaded motor shaft extending at least partially through said support head, said arbors being formed with anges whereby upon nesting thereof Within one another including said support head said iianges and said support head constitute pressure surfaces adapted to secure said sanding discs therebetween.

2. A motor driven rotatable head adapted and arranged to support a plurality of sanding discs thereon, said rotatable head being formed with a flange and having a bore extending inwardly medially therethrough, a primary and a secondary fitting, said primary fitting comprising a asesinos;

flanged arbor having course internal threads and being formed with an annular groove adjacent said fange, said secondary tting comprising a flanged arbor having coarse exterior threads and being formed with an anuular groove adjacent said ange, said primary fitting being adapted to be fitted in said rotatable head and the secondary tting being adapted to be screw threaded into said primary fitting and the annular grooves in both of said fittings being adapted to retain a sanding disc upon each thereof, the flange of said head and the flanges of the primary and secondary ttings constituting pressure surfaces adapted to compressively grip sanding discs in said annular grooves for functional use retention.

ARTHUR TUR'ION.

HENRY ELBERT HI-CKMAN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date Arnold July 7, 1903 Lorenz Sept. 28, 1920 Albertson Oct. 11, 1938 Siebert et al. f Oct. 28, 1941 Stever June 25, 1946 Stever Oct. 8, 1946 Watson Mar. 21, 1950 

